my compressor repair

[John Rudd]

Thought I'd start a new thread for the repair of my air compressor...
Having bought a new regulator that would not fit or that had useable parts I set about machining a new bonnet for the air regulator.

Having found a sizeable piece of alloy bar and playing around with thread cutting on the lathe, here are a few snaps I took along the way....

The picture below shows the main body of the regulator on my compressor



Now this is the old part of the regulator that I treid to repair but it melted when heated with a torch...( I said torch not flame thrower! )

[John Rudd]

Ok next up, I threaded some 32mm dia aluminium bar...Sort of a suck it and see job this...
The dia of the threads measured some 31.6 ish mm, but using metric thread gauges didnt tell me what pitch..None of the usual pitches didnt fit...

I guessed...I measured the pitch with my vernier, sort of around the 50 thou pitch , so I took a stab at 18-20 tpi...No idea what the thread angle is, so I stumped for 60 degrees...( plus I havent got a 55 degree tool )



After a few cuts,






 and time for a trial fit...



It might not be perfect but it fits without too much aggro...

[John Rudd]

After much more cutting, measuring and cussing...I got this far...



To finish the piece, I need to do a bit of boring for the spring to fit inside, the major hole you can see is for the piston that acts on the reg valve( which is mounted in the main body...)

I think I might make a brass insert to fit in the top and thread that, a bit harder wearing than the ally bar..What do you reckon? Good idea?

More to follow...

Time for tea..

[arnoldb]

Looks good John 

Yes, a brass (or even better IMHO, phosphor bronze) insert would definitely work better and would be smoother in operation as it would not tend to gall as much as the ally either.

 , Arnold

[j45on]

Watching with interest John as I think I have the same compressor 

[krv3000]

that looks good

[matthew_g]

Watching with interest John as I think I have the same compressor 

Yep I got a red one too :-)

[John Rudd]

Watching with interest John as I think I have the same compressor 

Yep I got a red one too :-)

Yeah,.....Maybe we should for a 'Red compressor club'?

Did some more today, I'll post up the pictures later but its looking good so far..

( ermm maybe I should come clean and say this is the mk2 version? The one in the preceding pictures I managed to damage it beyond recovery... )

[John Rudd]

Ok, more shop time and piccies...
Spent today machining the hex shoulder on the regulator bonnet and cutting the external thread...

Here's some blurring pictures, sorry for the quality but I'm no budding snapper...



Just for interest, here's all the parts that make up the regulator top works...Spring/piston/ bonnet the mainparts anyway..

[John Rudd]

and finally all assembled and working...




another shot..



So there we are...would have a cost a fortune to repair in a workshop if I'd had to pay for making the part, but hey that's what we do isnt it, make or repair things? 

[Trion]

I had a similar compressor problem before I owned any of my machinery. It was "repaired" by replacing the regulator with a steel plate that I ground round on the belt sander + a lot of silicone sealant. Now you have showed the proper way of doing it!

[bry1975]

Impressive work John! 

[bigmini]

I had a similar compressor problem before I owned any of my machinery. It was "repaired" by replacing the regulator with a steel plate that I ground round on the belt sander + a lot of silicone sealant. Now you have showed the proper way of doing it!

I have a compressor like yours. I did up the non regulated output too tight and cracked the housing which was wafer thin around the thread. I ended up replacing the whole assembly with a block of aluminium with holes drilled in it for a non-regulated output, a gauge, the pressure switch and a relief valve. I was nervous about whether my threads would hold, but I reckon it's stronger than the original - just no regulator. I think I see a way to modify it to take a regulator like the one you have made, so one more thing on the To Do list.

For now, I use a separate moisture trap and regulator in-line.

[krv3000]

o well thats me out of the red compressor club mines blue with a tuch of muck on it

[bigmini]

o well thats me out of the red compressor club mines blue with a tuch of muck on it

Mine is blue as well, and it probably has a bit more muck on it I think